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DateAlmanac

What is IST in ACST?

Australian Central Time is 4 hours ahead

India Standard Time is on UTC+5:30 and Australian Central Time is on UTC+9:30 right now. The gap changes during the year — see below.

Time in New Delhi
6:22:38 PM
Time in Adelaide
10:22:38 PM
Difference
+4 h
Next clock change
October 4, 2026

Convert a time

ACST — Australian Central Time

10:00 pm

ACST, Fri

When the difference changes

India Standard Time and Australian Central Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:

  1. Now – October 3, 2026Australian Central Time is 4 hours ahead
  2. October 3, 2026 – April 3, 2027Australian Central Time is 5 hours ahead
  3. April 3, 2027 – October 2, 2027Australian Central Time is 4 hours ahead
  4. October 2, 2027 – onwardsAustralian Central Time is 5 hours ahead

Periods shorter than a day are not listed. Each zone changes at its own local time, so on a date when both move there are a few hours when the gap is briefly something else.

Daylight saving

India Standard Time

No clock changes

India Standard Time stays on IST all year, so its offset from UTC never moves.

Australian Central Time

Sunday, October 4, 2026

Clocks go forward one hour — 2:00 am becomes 3:00 am local time, and the zone is on ACDT after that.

IST to ACST conversion table

Every hour of Friday, September 25, 2026, converted from India Standard Time to Australian Central Time. 4 of the 24 hours fall on a different calendar day in Adelaide, which is marked.

12:00 am IST
4:00 am ACST
1:00 am IST
5:00 am ACST
2:00 am IST
6:00 am ACST
3:00 am IST
7:00 am ACST
4:00 am IST
8:00 am ACST
5:00 am IST
9:00 am ACST
6:00 am IST
10:00 am ACST
7:00 am IST
11:00 am ACST
8:00 am IST
12:00 pm ACST
9:00 am IST
1:00 pm ACST
10:00 am IST
2:00 pm ACST
11:00 am IST
3:00 pm ACST
12:00 pm IST
4:00 pm ACST
1:00 pm IST
5:00 pm ACST
2:00 pm IST
6:00 pm ACST
3:00 pm IST
7:00 pm ACST
4:00 pm IST
8:00 pm ACST
5:00 pm IST
9:00 pm ACST
6:00 pm IST
10:00 pm ACST
7:00 pm IST
11:00 pm ACST
8:00 pm IST
12:00 am ACST+1 day
9:00 pm IST
1:00 am ACST+1 day
10:00 pm IST
2:00 am ACST+1 day
11:00 pm IST
3:00 am ACST+1 day

Scheduling between the two

Working hours overlap from 9:00 am to 2:00 pm IST, which is 1:00 pm to 6:00 pm ACST. Anything inside that window falls in the normal working day at both ends.

A note on IST: it can also mean Israel Standard Time (UTC+2) and Irish Standard Time (UTC+1). This page means India Standard Time, which is what almost all searches for IST want.

India Standard Time (IST) is used in all of India and Sri Lanka, on a single UTC+5:30 offset with no daylight saving

Australian Central Time (ACST) is used in South Australia and the Northern Territory, on a half-hour offset from the east coast

Other conversions